US4838665AExpiredUtility

Temperature-compensated lens system

72
Assignee: PIONEER ELECTRONIC CORPPriority: Jul 25, 1986Filed: Jul 27, 1987Granted: Jun 13, 1989
Est. expiryJul 25, 2006(expired)· nominal 20-yr term from priority
Inventors:Shinichi HasegawaTakayuki Yoshioka
G02B 13/18G02B 3/12G02B 13/16
72
PatentIndex Score
29
Cited by
4
References
38
Claims

Abstract

A temperature-compensated lens system of positive power includes a plastic lens having a convex surface, and a liquid lens of negative power made of a liquid or gel material and held against the convex surface of the plastic lens, the liquid lens having a temperature coefficient dn/dT ranging from -4×10 -4 to -2.0×10 -4 /°C. indicating the temperature-dependent variation in the refractive index of the liquid lens. The lens system is highly resistant to temperature-dependent variations.

Claims

exact text as granted — not AI-modified
We claim: 
     
       1. A temperature-compensated lens system comprising a plastic lens having a convex surface, and a liquid lens of negative power made of a liquid or gel material and held against said convex surface of said plastic lens, said liquid lens having a temperature coefficient dn/dT ranging from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, said lens system having positive power in its entirety. 
     
     
       2. A temperature-compensated lens system according to claim 1, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       3. A temperature-compensated lens system according to claim 1, wherein said liquid or gel material of the liquid lens comprises silicone oil or silicone gel. 
     
     
       4. A temperature compensated projection optical system, comprising: a screen;   an electron gun CRT, having a sheet from which optical beams are emitted toward said screen; and   an optical system of positive power disposed between said sheet and said screen and including a first plastic lens having a convex surface and a lens of negative power held against said convex surface with a temperature coefficient of refractive index ranging from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens.   
     
     
       5. A temperature compensated projection optical system as recited in claim 4, wherein said negative power lens comprises a liquid or gel material. 
     
     
       6. A temperature compensated projection optical system as recited in claim 5, further comprising a second plastic lens held against said negative power lens on a side opposite said first plastic lens. 
     
     
       7. A temperature compensated projection optical system as recited in claim 5, further comprising a lens of a liquid or gel material held against said sheet. 
     
     
       8. A temperature-compensated lens system comprising a first lens unit composed of a first plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said first plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, and a second plastic lens held against the other side surface of said liquid lens, and a second lens unit of positive power made of plastic. 
     
     
       9. A temperature-compensated lens system according to claim 8, wherein the lens surfaces of said first and second plastic lenses are made aspherical. 
     
     
       10. A temperature-compensated lens system according to claim 8, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       11. A temperature-compensated lens system according to claim 8, wherein said liquid lens is made of silicone oil. 
     
     
       12. A temperature-compensated lens system according to claim 8, wherein said liquid lens is made of silicone gel. 
     
     
       13. A temperature-compensated lens system comprising a first lens unit composed of a plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperaturedependent variation in the refractive index of the liquid lens, and a glass lens held against the other side surface of said liquid lens, and a second lens unit of positive power made of plastic. 
     
     
       14. A temperature-compensated lens system according to claim 13, wherein the lens surface of said plastic lens are made spherical. 
     
     
       15. A temperature-compensated lens system according to claim 13, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       16. A temperature-compensated lens system according to claim 13, wherein said liquid lens is made of silicone oil. 
     
     
       17. A temperature-compensated lens system according to claim 13, wherein said liquid lens is made of silicone gel. 
     
     
       18. A temperature-compensated lens system comprising a first lens unit composed of a first plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said first plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, and a second plastic lens held against the other side surface of said liquid lens, a second lens unit or positive power made of plastic, and a third lens unit located in front of a CRT gun, wherein said first lens unit is arranged so that a flux of light converging into a single point through said first lens unit passes through an area defined by 50% or more of an effective diameter of said first lens unit. 
     
     
       19. A temperature-compensated lens system according to claim 18, wherein the lens surface of said first and second plastic lenses are made aspherical. 
     
     
       20. A temperature-compensated lens system according to claim 18, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       21. A temperature-compensated lens system according to claim 18, wherein said liquid lens is made of silicone oil. 
     
     
       22. A temperature-compensated lens system according to claim 18, wherein said liquid lens is made of silicone gel. 
     
     
       23. A temperature-compensated lens system comprising a first lens unit composed of a plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, and a glass lens held against the other side surface of said liquid lens, a second lens unit of positive power made of plastic, and a third lens unit located in front of a CRT gun, wherein said first lens unit is arranged so that a flux of light converging into a single point through said first lens unit passes through an area defined by 50% or more of an effective diameter of said first lens unit. 
     
     
       24. A temperature-compensated lens system according to claim 23, wherein the lens surfaces of said plastic lens are made aspherical. 
     
     
       25. A temperature-compensated lens system according to claim 23, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       26. A temperature-compensated lens system according to claim 23, wherein said liquid lens is made of silicone oil. 
     
     
       27. A temperature-compensated lens system according to claim 23, wherein said liquid lens is made of silicone gel. 
     
     
       28. A temperature-compensated lens system comprising a first plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said first plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, and a second liquid lens held against the other side surface of said liquid lens, whereby temperature variation in refractive index of the overall lens system may be compensated for. 
     
     
       29. A temperature-compensated lens system according to claim 28, wherein the lens surfaces of said first and second plastic lenses are made aspherical. 
     
     
       30. A temperature-compensated lens system according to claim 28, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       31. A temperature-compensated lens system according to claim 28, wherein said liquid lens is made of silicone oil. 
     
     
       32. A temperature-compensated lens system according to claim 28, wherein said liquid lens is made of silicone gel. 
     
     
       33. A temperature-compensated lens system comprising a plastic lens having a convex surface, a liquid lens of negative power made of a liquid or gel material and held against said plastic lens, said liquid lens having a temperature coefficient dn/dT range from -4×10 -4  to -2.0×10 -4  /°C., said temperature coefficient indicative of a temperature-dependent variation in the refractive index of the liquid lens, and a glass lens held against the other side of the liquid lens, whereby temperature variation in refractive index of the overall lens system may be compensated for. 
     
     
       34. A temperature-compensated lens system according to claim 33, wherein the lens surface of said plastic lens and said glass lens are made aspherical. 
     
     
       35. A temperature-compensated lens system according to claim 33, wherein said liquid material of the liquid lens comprises a mixture of 20 to 100 weight % of glycerin and 80 to 0 weight % of ethylene glycol. 
     
     
       36. A temperature-compensated lens system according to claim 33, wherein said liquid lens is made of silicone oil. 
     
     
       37. A temperature-compensated lens system according to claim 33, wherein said liquid lens is made of silicone gel. 
     
     
       38. A temperature-compensated lens system according to claim 1, wherein said convex surface of said plastic lens is made aspherical.

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